It is important to be able to adapt (modify) the electrical connections between the pieces of equipment in an aircraft (in particular sensors, actuators, and computers), in particular in order to facilitate installing and maintaining pieces of equipment that are optional.
In order to avoid manufacturing specific bundles or harnesses for each equipment configuration, standard bundles or harnesses are provided, and pieces of equipment are connected using their respective bundles via a bundle interconnection device that is configurable/adaptable to different equipment configurations of the aircraft.
Such a device may include a matrix of pins, in particular a matrix of pins of juxtaposed connectors, together with a plurality of electrically conductive wires, with each wire or “strap” interconnecting two pins. Specifically for reasons of ensuring that pieces of equipment are interchangeable, the pins of the connectors fitted to the bundles or harnesses need not be “associated” with any specific electrical signal. As a result, such devices have large numbers of pins and straps.
The electrical and mechanical connection between the end of a segment of wire or strap and one of the pins of the device can be achieved by wrapping.
Given the high levels of vibration that such connections must be capable of accommodating, and also the necessary level of reliability required for such connections, manual or automatic wrapping of one end of a strap about a pin must be performed with very great precaution and must then be verified.
In addition, the pins or strap ends must be electrically insulated, e.g. by depositing or “impregnating” a layer of insulating plastics material.
In practice, such devices must enable several hundreds of harness conductor wires to be interconnected.
U.S. Pat. No. 5,348,482 describes a bundle junction box comprising a backplane, electronic cards pluggable to the backplane, together with one or more reconfigurable pluggable cards using straps or junctions made by wrapping or by flexible circuits; the backplane is constituted by a wall supporting connectors receiving the pluggable cards, the pins of said connectors being connected by flexible circuits to the pins of inlet/outlet connectors adapted to connectors fitted to harnesses.
Those devices that are reconfigurable by means of straps wrapped onto pins present the drawback of requiring the insulating covering to be removed whenever it is necessary to modify, eliminate, or add a strap; after having modified the straps configuration, a new layer of insulating covering must be deposited, and all of the wrapped connections must be tested anew; such operations are lengthy and expensive.
Proposals have also been made in French patent No. 2,822,130 for an interconnection module comprising a wall, on a first face of which there are provided connectors for connecting with connection cords, and on a second face of which there are provided connectors that receive three types of pluggable card:                cross-connect cards each comprising a printed circuit with tracks for providing terminal-to-terminal connection with connection cords;        connection and cross-connect cards having connectors adapted to the harness end-connectors; and        connection and cross-connect cards that can be modified by manually installing straps.        
Such a device is not adapted to rotary wing aircraft in which there is no need to connect interconnection modules via identical cords.